U.S. patent application number 17/537709 was filed with the patent office on 2022-06-09 for network system.
The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Tomohisa KISHIGAMI, Akira TADA.
Application Number | 20220179663 17/537709 |
Document ID | / |
Family ID | 1000006049911 |
Filed Date | 2022-06-09 |
United States Patent
Application |
20220179663 |
Kind Code |
A1 |
TADA; Akira ; et
al. |
June 9, 2022 |
NETWORK SYSTEM
Abstract
A network system includes at least one transmission path and a
plurality of terminal devices each connected to the transmission
path. Each of the terminal devices includes a transceiver, a
startup processing unit, and a switching unit. The transceiver is
configured to operate either one of a first standby unit and a
second standby unit according to a switching instruction. The
switching unit is configured to output the switching instruction to
the transceiver to operate the second standby unit when a
transmission path empty period lasts for a predetermined
preparation time or more after a non-designation period has lasted
for a predetermined operation determination time or more.
Inventors: |
TADA; Akira; (Kariya-city,
JP) ; KISHIGAMI; Tomohisa; (Kariya-city, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city |
|
JP |
|
|
Family ID: |
1000006049911 |
Appl. No.: |
17/537709 |
Filed: |
November 30, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 12/10 20130101;
G06F 9/4418 20130101 |
International
Class: |
G06F 9/4401 20060101
G06F009/4401; H04L 12/10 20060101 H04L012/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2020 |
JP |
2020-201229 |
Claims
1. A network system comprising: at least one transmission path; and
a plurality of terminal devices each connected to the transmission
path, wherein each of the terminal devices includes: a transceiver
having: a first standby unit that is configured to change the
terminal device from a sleep state where a designation function is
stopped to a wakeup state where the designation function is
executable when receiving a designation management frame that is a
type of a communication frame transmitted and received through the
transmission path and that is given at least startup information
necessary for identifying a startup group to which the terminal
device belongs; and a second standby unit that is configured to
change the terminal device from the sleep state to the wakeup state
when receiving any communication frame, wherein the second standby
unit is configured to operate with power consumption lower than the
first standby unit, wherein the transceiver is configured to
operate either one of the first standby unit and the second standby
unit according to a switching instruction; a startup processing
unit configured to: transmit the designation management frame to
the transmission path while an internal factor continues when the
terminal device wakes up by the internal factor that is a factor
other than that of receiving the designation management frame; and
not transmit the designation management frame to the transmission
path when the internal factor is not generated; and a switching
unit configured to output the switching instruction to the
transceiver to operate the second standby unit when a transmission
path empty period during which the communication frame is neither
transmitted nor received through the transmission path lasts for a
predetermined preparation time or more after a non-designation
period during which the designation management frame is not
received through the transmission path has lasted for a
predetermined operation determination time or more.
2. The network system according to claim 1, wherein the switching
unit includes: an empty period determination unit that is
configured to determine whether the transmission path empty period
is equal to or more than the preparation time after the
non-designation period has lasted for the operation determination
time or more; a first switching execution unit that is configured
to output the switching instruction to the transceiver to operate
the first standby unit when the empty period determination unit
determines that the transmission path empty period is less than the
preparation time after the non-designation period has lasted for
the operation determination time or more; and a second switching
execution unit that is configured to output the switching
instruction to the transceiver to operate the second standby unit
when the empty period determination unit determines that the
transmission path empty period is equal to or more than the
preparation time after the non-designation period has lasted for
the operation determination time or more.
3. The network system according to claim 2, further comprising: at
least one monitoring startup unit, wherein the at least one
monitoring startup unit is configured to transmit a particular
startup frame that is a type of the communication frame to wake up
all the terminal devices connected to the transmission path when a
predetermined condition is satisfied, the first standby unit is
configured to change the terminal device from the sleep state to
the wakeup state when receiving the particular startup frame, the
second standby unit is configured to change the terminal device
from the sleep state to the wakeup state when receiving the
particular startup frame, and the switching unit is configured to
output the switching instruction to the transceiver to operate the
second standby unit when the transmission path empty period is
determined to be equal to or more than the preparation time after
(i) the terminal device woke up by receiving the particular startup
frame and then (ii) the non-designation period has lasted for the
operation determination time or more.
4. The network system according to claim 3, further comprising: at
least one relay device configured to connect a plurality of
transmission paths to each other, wherein the relay device includes
the monitoring startup unit, and the monitoring startup unit is
configured to: measure the transmission path empty period; and
transmit the particular startup frame when the transmission path
empty period lasts for a predetermined monitoring time or more that
is longer than the preparation time.
5. The network system according to claim 3, wherein the terminal
device further includes: the monitoring startup unit; a startup
storage unit configured to store information that the terminal
device wakes up by the particular startup frame; and a startup
determination unit configured to determine whether the terminal
device wakes up by the particular startup frame, and the switching
unit is configured to: cause the monitoring startup unit to
transmit the particular startup frame to the transmission path when
the transmission path empty period lasts for the preparation time
or more after the non-designation period has lasted for the
operation determination time or more and when the startup
determination unit determines that the terminal device does not
wake up by the particular startup frame; and output the switching
instruction to the transceiver to operate the second standby unit
when the transmission path empty period lasts for the preparation
time or more after the non-designation period has lasted for the
operation determination time or more and when the startup
determination unit determines that the terminal device wakes up by
the particular startup frame.
6. The network system according to claim 1, further comprising at
least one monitoring startup unit, wherein the monitoring startup
unit is configured to: measure the transmission path empty period;
and transmit a particular startup frame that is a type of the
communication frame to wake up all the terminal devices connected
to the transmission path when the transmission path empty period
lasts for a predetermined monitoring time or more that is longer
than at least the preparation time, the first standby unit is
configured to change the terminal device from the sleep state to
the wakeup state when receiving the particular startup frame; the
second standby unit is configured to change the terminal device
from the sleep state to the wakeup state when receiving the
particular startup frame; the terminal device further includes: a
startup storage unit that is configured to store information that
the terminal device wakes up by the particular startup frame; and a
startup determination unit that is configured to determine whether
the terminal device wakes up by the particular startup frame, and
the switching unit is configured to, when the non-designation
period lasts for the operation determination time or more after the
terminal device waked up: output the switching instruction to the
transceiver to operate the first standby unit when the startup
determination unit determines that the terminal device wakes up by
the communication frame other than the particular startup frame;
and output the switching instruction to the transceiver to operate
the second standby unit when the startup determination unit
determines that the terminal device wakes up by the particular
startup frame.
7. The network system according to claim 6, further comprising: at
least one relay device configured to connect a plurality of
transmission paths to each other, wherein the relay device includes
the monitoring startup unit.
8. The network system according to claim 6, wherein at least one
predetermined terminal device of the plurality of terminal devices
includes the monitoring startup unit.
9. The network system according to claim 1, wherein the switching
unit is configured to output the switching instruction to the
transceiver to supply electricity to the second standby unit.
10. The network system according to claim 1, wherein the switching
unit is configured to output the switching instruction to the
transceiver to supply, to the second standby unit, a clock signal
for driving the second standby unit.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on Japanese Patent Application No.
2020-201229 filed on Dec. 3, 2020, the disclosure of which is
incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to a network system that is
configured to reduce power consumption.
BACKGROUND
[0003] A vehicle is equipped with a large number of electronic
control units, so-called ECUs, to control in-vehicle equipment.
These ECUs are connected to a communication bus, thereby building a
network system that uses the ECUs as nodes. For such a network
system, there has been known a technique called a partial network
that reduces power consumption in the whole network system by,
according to the state, bringing some ECUs unnecessary for control
into a sleep state where the functions of the ECUs are stopped.
SUMMARY
[0004] According to one aspect of the present disclosure, a network
system including at least one transmission path and a plurality of
terminal devices each connected to the transmission path. Each of
the terminal devices includes a transceiver, a startup processing
unit, and a switching unit. The transceiver includes a first
standby unit and a second standby unit and is configured to operate
either one of the first standby unit and the second standby unit
according to a switching instruction.
[0005] The first standby unit is configured to change the terminal
device from a sleep state where a designation function is stopped
to a wakeup state where the designation function is executable when
receiving a designation management frame. The designation
management frame is a type of a communication frame transmitted and
received through the transmission path and is given at least
startup information necessary for identifying a startup group to
which the terminal device belongs. The second standby unit is
configured to change the terminal device from the sleep state to
the wakeup state when receiving any communication frame. The second
standby unit is configured to operate with power consumption lower
than the first standby unit.
[0006] The startup processing unit is configured to: transmit the
designation management frame to the transmission path while an
internal factor continues when the terminal device wakes up by the
internal factor that is a factor other than that of receiving the
designation management frame; and not transmit the designation
management frame to the transmission path when the internal factor
is not generated.
[0007] The switching unit is configured to output the switching
instruction to the transceiver to operate the second standby unit
when a transmission path empty period during which the
communication frame is neither transmitted nor received through the
transmission path lasts for a predetermined preparation time or
more after a non-designation period during which the designation
management frame is not received through the transmission path has
lasted for a predetermined operation determination time or
more.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a block diagram illustrating the configuration of
a network system of a first embodiment;
[0009] FIG. 2 is an explanatory view illustrating startup
groups;
[0010] FIG. 3 is an explanatory view illustrating belonging
information held by terminal devices and startup information
assigned to an NM frame;
[0011] FIG. 4 is a block diagram illustrating the configuration of
a relay device;
[0012] FIG. 5 is a block diagram illustrating the configuration of
the terminal device;
[0013] FIG. 6 is a flowchart illustrating the content of startup
control executed by a transceiver included in the terminal
device;
[0014] FIG. 7 is a flowchart illustrating the content of startup
control executed by a transceiver included in the relay device;
[0015] FIG. 8 is a flowchart of startup maintenance processing
executed by an MCU of the terminal device;
[0016] FIG. 9 is a flowchart of monitoring startup processing
executed by an MCU of the relay device;
[0017] FIG. 10 is an explanatory view explaining the operation of
the terminal device;
[0018] FIG. 11 is an explanatory view explaining the operation of
the network system;
[0019] FIG. 12 is a block diagram illustrating the configuration of
a network system of a second embodiment;
[0020] FIG. 13 is a flowchart of the startup maintenance processing
executed by the MCU of the terminal device;
[0021] FIG. 14 is a flowchart of the startup maintenance processing
executed by the MCU of the terminal device of a third embodiment;
and
[0022] FIG. 15 is a block diagram illustrating the configuration of
a transceiver of a terminal device of a fourth embodiment.
DETAILED DESCRIPTION
[0023] To begin with, a relevant technology of the present
disclosure will be described only for understanding the following
embodiments.
[0024] As a result of the detailed study by the present inventors,
a problem that in the conventional art, power consumption when the
ECUs are in the sleep state is desired to be reduced in the partial
network has been found out.
[0025] One aspect of this disclosure provides a technique for
reducing, in a partial network, power consumption when ECUs are in
a sleep state.
[0026] As described above, according to the one aspect of the
present disclosure, a network system including at least one
transmission path and a plurality of terminal devices each
connected to the transmission path. Each of the terminal devices
includes a transceiver, a startup processing unit, and a switching
unit. The transceiver includes a first standby unit and a second
standby unit and is configured to operate either one of the first
standby unit and the second standby unit according to a switching
instruction.
[0027] The first standby unit is configured to change the terminal
device from a sleep state where a designation function is stopped
to a wakeup state where the designation function is executable when
receiving a designation management frame. The designation
management frame is a type of a communication frame transmitted and
received through the transmission path and is given at least
startup information necessary for identifying a startup group to
which the terminal device belongs. The second standby unit is
configured to change the terminal device from the sleep state to
the wakeup state when receiving any communication frame. The second
standby unit is configured to operate with power consumption lower
than the first standby unit.
[0028] The startup processing unit is configured to: transmit the
designation management frame to the transmission path while an
internal factor continues when the terminal device wakes up by the
internal factor that is a factor other than that of receiving the
designation management frame; and not transmit the designation
management frame to the transmission path when the internal factor
is not generated.
[0029] The switching unit is configured to output the switching
instruction to the transceiver to operate the second standby unit
when a transmission path empty period during which the
communication frame is neither transmitted nor received through the
transmission path lasts for a predetermined preparation time or
more after a non-designation period during which the designation
management frame is not received through the transmission path has
lasted for a predetermined operation determination time or
more.
[0030] According to such a configuration, the terminal device is
configured to switch the first standby unit and the second standby
unit. Thus, power consumption can be reduced, for example, in
sleeping, by operating the second standby unit rather than by
operating the first standby unit.
[0031] In addition, the terminal device operates the second standby
unit when the non-designation period is the operation determination
time or more and the transmission path empty period continues for
the preparation time or more. In other words, the terminal device
operates the second standby unit when the terminal devices in the
same startup group do not wake up by the internal factor and the
transmission path is empty. Thus, when the terminal devices in the
same startup group do not wake up and the transmission path is
empty, power consumption when the terminal devices sleep can be
reduced in the network system.
[0032] Next, a plurality of embodiments of the present disclosure
will be described below with reference to the drawings.
1. First Embodiment
[0033] [1-1. Overall Configuration]
[0034] A network system 1 illustrated in FIG. 1 includes at least
one bus-like transmission path (hereinafter, a bus 2), and a
plurality of terminal devices 5 each connected to the bus 2. For
example, in FIG. 1, the network system 1 includes three buses 2,
five terminal devices 5, and further, one relay device 4, but the
number of buses 2, the number of terminal devices 5, and the number
of relay devices 4 of the network system 1 are not limited to
these. Also, the network system 1 is not necessarily required to
include the relay device 4. Hereinafter, the relay device 4 is also
denoted as GW. The GW is an abbreviation for Gateway.
[0035] The plurality of buses 2 are connected to each other through
the relay device 4 to form a network. Each of the terminal devices
5 is connected to one of the plurality of buses 2. In this
embodiment, the terminal device 5 is also collectively called a
node.
[0036] The network system 1 forms a partial network that is an
electric supply control technique on the basis of the communication
control of the CAN protocol standard defined in ISO 11898-6: 2013.
The CAN is a registered trademark. The partial network achieves low
power consumption by waking up (that is, starting up) each node or
causing each node to sleep (that is, to hibernate), if necessary.
By waking up, the node turns into a normal operation state where a
function assigned to the node (hereinafter, also referred to as a
designation function) is usable without being limited, and by
sleeping, turns into a low power consumption operation state where
the usable function is limited.
[0037] In this embodiment, the terminal device 5 is an ECU. The ECU
is an abbreviation for Electronic Control Unit. At the time of
waking up, the terminal device 5 forms a startup group Gr.alpha.
together with other terminal devices 5 that need to start up at the
same time. The startup group includes at least one terminal device
5. An example of the startup groups in this embodiment is
illustrated in FIG. 2.
[0038] Each of the buses 2 is represented as 2_i, and the terminal
device 5 connected to the bus 2_i and belonging to the startup
group Gr.alpha. is represented as ECU_i.alpha.. The terminal device
5 belonging to a plurality of startup groups is represented as
ECU_i.alpha..beta. . . . . However, i=1, 2, 3, . . . , and .alpha.,
.beta.=A, B, C, . . . . For example, ECU_1BC means the terminal
device 5 connected to the bus 2_1 and belonging to two startup
groups GrB and GrC.
[0039] When waking up the node in the sleep state, the network
system 1 uses an NM frame that is a CAN frame including startup
information. The startup information is the information for
designating the startup group to which each node belongs. The NM is
an abbreviation for Network Management. The CAN frame corresponds
to a type of a communication frame transmitted and received on the
bus 2. Also, the NM frame is a type of the communication frame
transmitted and received on the bus 2, and corresponds to a
management frame.
[0040] The startup information designates at least one terminal
device 5. The startup information is set, for example, as
illustrated in FIG. 3. DLC is an abbreviation for Data Length Code,
and is the region in which the data region size of the CAN frame is
represented in bytes. That is, in the NM frame, the startup
information is stored in the data region of the CAN frame. Here,
for simplifying the description, the case where the DLC has 1 byte
(that is, 8 bits) is shown. The startup group is assigned to each
bit of the 8-bit data representing the startup information.
[0041] For example, in FIG. 3, in the 8-bit data representing the
startup information, the high order 3 bits have not been used, and
the low order 5 bits represent the ECU startup groups GrA to GrE.
However, in the network configuration illustrated in FIG. 1, the
GrD and GrE have not been used.
[0042] For the startup information set to the NW frame, the bit
corresponding to the startup group as a startup target is set to 1.
Hereinafter, the bit representing the startup group Gr.alpha. is
sometimes represented as PNC_.alpha.. However, .alpha.=A, B, C, . .
. . For example, in FIG. 3, in the 8-bit data representing the
startup information, the fifth bit counted from the low order
represents the startup group GrA, and this bit is represented as
PNC_A.
[0043] That is, in FIG. 3, PNC_A=0, PNC_B=1, PNC_C=0, PNC_D=0, and
PNC_E=0. The NM frame illustrated in FIG. 3 is the NM frame for
waking up the node belonging to the startup group GrB (that is, the
terminal device 5).
[0044] [1-1-1. The Configuration of the Relay Device]
[0045] As illustrated in FIG. 4, the relay device 4 having a relay
function is the so-called GW, and includes a transceiver 41, an MCU
43, and a power supply relay 44. The MCU is an abbreviation for
Micro Control Unit.
[0046] The transceiver 41 always receives electric supply. The MCU
43 receives electric supply through the power supply relay 44. The
relay device 4 may include a plurality of transceivers 41 according
to the number of the buses 2 connected. For example, in this
embodiment, the relay device 4 may include three transceivers 41
according to three buses 2, such as the buses 2_1 to 2_3.
[0047] The transceiver 41 is a transceiver incompatible with the
standard of the partial network (hereinafter, a PN-incompatible
transceiver), and transmits and receives a signal through the bus
2. The transceiver 41 includes a transmission/reception circuit
411. The transmission/reception circuit 411 generates the
communication frame following the CAN protocol according to
transmission data supplied from the MCU 43, and transmits the
communication frame to the bus 2.
[0048] When detecting the reception of any communication frame, the
transmission/reception circuit 411 outputs a startup instruction to
the power supply relay 44 irrespective of the type and content of
the communication frame. Thus, the relay device 4 wakes up. The
transmission/reception circuit 411 supplies the communication frame
received through the bus 2 to the MCU 43.
[0049] The MCU 43 includes a CPU 431, and a semiconductor memory,
such as, for example, a ROM or a RAM (hereinafter, a memory
432).
[0050] When starting up by starting the electric supply, the MCU 43
at least executes so-called frame relay processing for executing
the relay function, although not illustrated.
[0051] In this embodiment, further, the MCU 43 executes monitoring
startup processing for executing a monitoring function monitoring
the empty state of the bus 2 and an all wakeup function waking up
all the nodes connected to the buses 2. The memory 432 of the MCU
43 at least stores a program for executing the frame relay
processing and the monitoring startup processing.
[0052] With the relay function, the relay device 4, when receiving
the communication frame, wakes up the MCU 43 irrespective of the
type and content of the communication frame, and performs the
broadcasting of the received communication frame. The broadcasting
means the transmission to all the buses 2 connected to the relay
device 4. For example, the relay device 4 transmits the
communication frame received from the bus 2_1 to the bus 2_2 to the
bus 2_3.
[0053] The power supply relay 44 stops the electric supply to the
MCU 43 according to a stop instruction (that is, an instruction for
turning off the power supply relay 44), and causes the MCU 43 to
sleep. Thus, the relay device 4 sleeps. In this embodiment, the
stop instruction is outputted in the monitoring startup processing
executed by the MCU 43.
[0054] [1-1-2. The Configuration of the Terminal Device]
[0055] As illustrated in FIG. 5, the ECU as the terminal device 5
includes a transceiver 51, an MCU 53, a power supply relay 54, and
a state detection unit 55. The MCU 53 receives electric supply
through the power supply relay 54.
[0056] The transceiver 51 includes a transmission/reception circuit
511, a detection unit 515, a power supply switch 516, and a state
discrimination switch 517. The transmission/reception circuit 511,
the power supply switch 516, and the state discrimination switch
517 always receive electric supply. The detection unit 515 receives
electric supply through the power supply switch 516. The
transceiver 51 operates as a PN-compatible transceiver when
receiving the electric supply to the detection unit 515 through the
power supply switch 516. The transceiver 51 operates as a
transceiver incompatible with the standard of the partial network
(hereinafter, a PN-incompatible transceiver) when the electric
supply to the detection unit 515 stops.
[0057] The detection unit 515 is needed in order to operate the
transceiver 51 as the PN-compatible transceiver. The detection unit
515 includes a protocol detector 512, a frame configuration memory
513, and a message filter 514.
[0058] The transmission/reception circuit 511 has the same function
as the transmission/reception circuit 411 that configures the
transceiver 41 of the relay device 4 described with reference to
FIG. 4. That is, the transmission/reception circuit 511 generates
the communication frame following the CAN protocol according to
transmission data supplied from the MCU 53, and transmits the
communication frame to the bus 2. The transmission/reception
circuit 511 supplies the communication frame received through the
bus 2 to the MCU 53. In addition, when detecting the reception of
the communication frame, the transmission/reception circuit 511
outputs a startup instruction irrespective of the type and content
of the communication frame. The startup instruction outputted by
the transmission/reception circuit 511 is outputted through the
state discrimination switch 517 to the power supply relay 54.
[0059] When the communication frame received by the
transmission/reception circuit 511 is the NM frame used for the
control waking up the node, the protocol detector 512 extracts the
startup information shown in the data region of the NM frame, and
supplies the startup information to the message filter 514.
[0060] The frame configuration memory 513 stores belonging
information representing the startup group to which a self-node
belongs. The stored content of the frame configuration memory 513
may be configured to be able to be rewritten by the MCU 53. The
belonging information has the same data length as the startup
information, and has each bit assigned like the startup
information. For the belonging information stored in the frame
configuration memory 513, the bit corresponding to the startup
group to which the self-node belongs is set to 1.
[0061] The message filter 514 compares the startup information
extracted from the NM frame and the belonging information stored in
the frame configuration memory 513, and determines whether or not
the startup information includes the information designating the
self-node. For example, the startup information and the belonging
information are subjected to logical AND operation for each bit,
and when the operation result is not zero, it is determined that
the startup information includes the information designating the
self-node. When determining that the startup information includes
the information designating the self-node, the message filter 514
outputs the startup instruction. In this embodiment, the message
filter 514 outputs the startup instruction to the state
discrimination switch 517.
[0062] For example, each of the plurality of terminal devices 5
illustrated in FIG. 1 stores the belonging information illustrated
in FIG. 3 in the frame configuration memory 513. For example, as
illustrated in FIG. 3, at the reception of the NM frame as PNC_B=1,
the message filter 514 of the transceiver 51 of the terminal device
5 belonging to the GrB outputs the startup instruction to the state
discrimination switch 517. The terminal devices 5 belonging to the
GrB are the ECU_2B, ECU_1BC, and ECU3AB.
[0063] The power supply switch 516 executes or stops the electric
supply to the detection unit 515 according to a switching
instruction from the MCU 53. The switching instruction includes a
first switching instruction and a second switching instruction. The
first switching instruction is the switching instruction for
operating a first standby unit described later. The second
switching instruction is the switching instruction for operating a
second standby unit described later. In this embodiment, the power
supply switch 516 executes the electric supply to the detection
unit 515 according to the first switching instruction, and stops
the electric supply to the detection unit 515 according to the
second switching instruction. Hereinafter, when not discriminated,
the first switching instruction and the second switching
instruction are simply referred as the switching instructions. The
switching instruction is outputted from the MCU 53 through a signal
line 561.
[0064] In addition, the power supply switch 516 executes the
electric supply to the detection unit 515 according to a wakeup
instruction from the MCU 53. The wakeup instruction is outputted
from the MCU 53 through a signal line 562.
[0065] The state discrimination switch 517 switches the
transmission source of the startup instruction to the power supply
relay 54, to one of the transmission/reception circuit 511 and the
detection unit 515 according to the switching instruction from the
MCU 53. When the electric supply to the detection unit 515 is
executed according to the first switching instruction, the state
discrimination switch 517 sets the transmission source of the
startup instruction to the power supply relay 54 as the detection
unit 515 according to the first switching instruction. When the
electric supply to the detection unit 515 is stopped according to
the second switching instruction, the state discrimination switch
517 sets the transmission source of the startup instruction to the
power supply relay 54 as the transmission/reception circuit 511
according to the second switching instruction.
[0066] In this way, the transceiver 51 operates as the
PN-compatible transceiver when electricity is supplied to the
detection unit 515, and operates as the PN-incompatible transceiver
when the electric supply to the detection unit 515 stops. That is,
the transceiver 51 is switched to one of the PN-compatible
transceiver and the PN-incompatible transceiver according to the
switching instruction.
[0067] In this embodiment, all the configurations included in the
transceiver 51 correspond to the first standby unit, and the
configurations excluding the detection unit 515 from all the
configurations included in the transceiver 51 correspond to the
second standby unit. That is, the second standby unit includes some
components of the first standby unit, and operates with power
consumption lower than the power consumption of the first standby
unit.
[0068] In this embodiment, the transceiver 51 supplies electricity
to one of the first standby unit and the second standby unit
according to the switching instruction. The first standby unit
causes the terminal device 5 to make a transition from the sleep
state to the wakeup state when receiving the NM frame assigned the
startup information designating the terminal device 5 (that is, a
designation management frame). The second standby unit causes the
terminal device 5 to make a transition from the sleep state to the
wakeup state when receiving any communication frame.
[0069] In this embodiment, the power supply switch 516 and the
state discrimination switch 517 are included in the transceiver 51,
but for example, at least one of the power supply switch 516 and
the state discrimination switch 517 may be included in the terminal
device 5, without being included in the transceiver 51.
[0070] Hereinafter, of the sleep states of the terminal device 5,
the state where the detection unit 515 receives the electric supply
and operates as the PN-compatible transceiver (that is, the state
where the first standby unit operates) is also referred to as
selective sleep. In addition, of the sleep states of the terminal
device 5, the state where the detection unit 515 does not receive
the electric supply and operates as the PN-incompatible transceiver
(that is, the state where the second standby unit operates) is also
referred to as standard sleep.
[0071] The state detection unit 55 uses a detection function
assigned to the self-node, and determines whether or not the
self-node is in the state of being required to wake up. When the
self-node is in the state of being required to wake up, the state
detection unit 55 outputs the startup instruction (hereinafter, the
startup instruction by an internal factor) to the power supply
relay 54.
[0072] The power supply relay 54 starts the electric supply to the
MCU 53 according to the startup instruction from the transceiver 51
or the state detection unit 55, thereby waking up the MCU 53.
[0073] The power supply relay 54 notifies a wakeup factor to the
MCU 53. The wakeup factor here is one of the startup instruction by
the reception of any communication frame or the reception of the NM
frame from the transceiver 51 (hereinafter, also referred to as an
external factor), and the startup instruction by the internal
factor from the state detection unit 55.
[0074] Also, the power supply relay 54 stops the electric supply to
the MCU 53 according to a stop instruction (that is, an instruction
for turning off the power supply relay 54), thereby causing the MCU
53 to sleep. In this embodiment, the stop instruction is outputted
through a signal line 563 in startup maintenance processing
executed by the MCU 53.
[0075] Like the above-described MCU 43, the MCU 53 includes a CPU
531, and a semiconductor memory, such as, for example, a ROM or a
RAM (hereinafter, a memory 532).
[0076] When starting up by starting the electric supply, the MCU 53
at least executes the startup maintenance processing. In addition,
when starting up, the MCU 53 executes processing for executing the
function assigned to the self-node (that is, the designation
function). The memory 532 of the MCU 53 at least stores the
belonging information also stored in the frame configuration memory
513, in addition to a program for executing the startup maintenance
processing and the processing for executing the function assigned
to the self-node.
[0077] [1-2. The Startup Control by the Transceiver]
[0078] [1-2-1. The Startup Control by the Transceiver of the
Terminal Device]
[0079] The content of the startup control executed by the
transceiver 51 of each node will be described with reference to the
flowchart in FIG. 6. The startup control is continuously executed
while the electric supply to the node is performed. In FIG. 6, the
transceiver 51 sets the standard sleep as an initial state. That
is, the power supply switch 516 stops the electric supply to the
detection unit 515 according to the second switching instruction
outputted from the MCU 53, and the state discrimination switch 517
selects the transmission/reception circuit 511 as the transmission
source of the startup instruction.
[0080] However, the transceiver 51 may set the selective sleep as
the initial state. When setting the selective sleep as the initial
state, the transceiver 51 starts the processing from S125.
[0081] In S100, the transceiver 51 determines whether or not the
communication frame has been received. The communication frame here
is any communication frame. The transceiver 51 is standby by
repeating the same step when the communication frame has not been
received, and shifts the processing to S105 when the communication
frame has been received. The S100 is executed by the
transmission/reception circuit 511.
[0082] In the S105, the transceiver 51 outputs the startup
instruction (that is, the instruction for turning on the power
supply relay 54) through the state discrimination switch 517 to the
power supply relay 54. The power supply relay 54 that has received
the startup instruction starts the electric supply to the MCU 53 to
start up the MCU 53. The startup instruction here is outputted from
the transmission/reception circuit 511. Thus, the terminal device 5
makes a transition from the sleep state to the wakeup state (that
is, wakes up). The power supply switch 516 executes the electric
supply to the detection unit 515 according to the wakeup
instruction outputted from the MCU 53 that has woken up. Also, the
state discrimination switch 517 switches the transmission source of
the startup instruction, and selects, as the transmission source of
the startup instruction, the detection unit 515, not the
transmission/reception circuit 511.
[0083] In subsequent S110, the transceiver 51 determines whether or
not the startup maintenance condition has been established. The
transceiver 51 is standby by repeating the same step when the
startup maintenance condition has been established, and shifts the
processing to S115 when the startup maintenance condition has not
been established.
[0084] In the subsequent S115, the transceiver 51 determines
whether or not the terminal device 5 is caused to perform the
standard sleep. When determining that the terminal device 5 is
caused to perform the standard sleep, the transceiver 51 shifts the
processing to S120, and causes the terminal device 5 to perform the
standard sleep. When determining that the terminal device 5 is not
caused to perform the standard sleep (that is, is caused to perform
the selective sleep), the transceiver 51 shifts the processing to
S125, and causes the terminal device 5 to perform the selective
sleep.
[0085] For example, in this embodiment, the processing in the S110
to the S115 is executed by the state discrimination switch 517. The
processing in the S120 to the S125 are executed by the power supply
switch 516.
[0086] That is, when not newly receiving the switching instruction
from the MCU 53, the state discrimination switch 517 determines
that the startup maintenance condition has been established, and
holds the switching state to be standby (that is, when it is
determined as positive in the S110).
[0087] Here, when newly receiving the switching instruction from
the MCU 53, the state discrimination switch 517 determines that the
startup maintenance condition has not been established, and when
the switching instruction is the second switching instruction, the
state discrimination switch 517 determines that the terminal device
5 is caused to perform the standard sleep. The state discrimination
switch 517 selects the transmission/reception circuit 511 as the
transmission source of the startup instruction according to the
second switching instruction (that is, when it is determined as
positive in the S115).
[0088] The power supply switch 516 stops the electric supply to the
detection unit 515 according to the above-described second
switching instruction, and causes the transceiver 51 to make a
transition to the state corresponding to the standard sleep (that
is, the PN-incompatible transceiver) (that is, the S120). At this
time, the stop instruction is outputted from the MCU 53 to the
power supply relay 54. Thus, the terminal device 5 performs the
standard sleep.
[0089] On the other hand, when newly receiving the switching
instruction from the MCU 53, the state discrimination switch 517
determines that the startup maintenance condition has not been
established, and when the switching instruction is the first
switching instruction, determines that the terminal device 5 is
caused to perform the selective sleep. The state discrimination
switch 517 selects the detection unit 515 as the transmission
source of the startup instruction according to the first switching
instruction (that is, when it is determined as negative in the
S115). The power supply switch 516 performs the electric supply to
the detection unit 515 according to the above-described first
switching instruction, and causes the transceiver 51 to make a
transition to the state corresponding to the selective sleep (that
is, the PN-compatible transceiver) (that is, the S125). At this
time, the stop instruction is outputted from the MCU 53 to the
power supply relay 54. Thus, the terminal device 5 performs the
selective sleep.
[0090] In subsequent S130, the transceiver 51 operating as the
PN-compatible transceiver determines whether or not the NM frame
has been received. This determination is executed by the protocol
detector 512. The transceiver 51 is standby by repeating the same
step when having not received the NM frame, and shifts the
processing to S135 when having received the NM frame.
[0091] In the S135, the transceiver 51 determines whether or not
the startup group to which the self-node belongs is included in the
startup information shown in the data region of the received NM
frame, that is, whether or not the self-node is the startup target.
This determination is executed by the frame configuration memory
513 and the message filter 514.
[0092] The transceiver 51 shifts the processing to S140 when
determining that the self-node is the startup target, and returns
the processing to the S130 when determining that the self-node is
not the startup target.
[0093] Like the S105, in the S140, the transceiver 51 starts up the
MCU 53. Like the S105, in the transceiver 51, the power supply
switch 516 executes the electric supply to the detection unit 515
according to the wakeup instruction outputted from the MCU 53, and
the state discrimination switch 517 selects the detection unit 515
as the transmission source of the startup instruction.
[0094] In subsequent S145 to S150, the transceiver 51 operates like
the S110 to the S115. However, in the S150, the transceiver 51
returns the processing to the S125 when the switching instruction
newly received from the MCU is the first switching instruction, and
shifts the processing to the S120 when the switching instruction is
the second switching instruction.
[0095] That is, when the switching instruction is the first
switching instruction (that is, when it is determined as positive
in the S150), the power supply switch 516 continues the electric
supply to the detection unit 515, and causes the transceiver 51 to
make a transition to the state corresponding to the selective sleep
(that is, the PN-compatible transceiver). Also, when the switching
instruction is the second switching instruction (that is, when it
is determined as negative in the S150), the power supply switch 516
stops the electric supply to the detection unit 515, and causes the
transceiver 51 to make a transition to the state corresponding to
the standard sleep (that is, the PN-incompatible transceiver).
[0096] [1-2-2. The Startup Control by the Transceiver of the Relay
Device]
[0097] The content of the startup control executed by the
transceiver 41 included in the relay device 4 will be described
with reference to the flowchart in FIG. 7. The startup control is
executed while the electric supply to the relay device 4 is
performed.
[0098] In S160 to S165, when receiving the communication frame, the
transceiver 41 operating as the PN-incompatible transceiver outputs
the startup instruction (that is, the instruction for turning on
the power supply relay 44) to the power supply relay 44
irrespective of the type of the communication frame. The power
supply relay 44 that has received the startup instruction starts
the electric supply to the MCU 43, and starts up the MCU 43. Thus,
the relay device 4 wakes up. The relay device 4 executes the relay
function while waking up.
[0099] In S170, the transceiver 41 determines whether or not the
startup maintenance condition has been established, is standby by
repeating the same step when the startup maintenance condition has
been established, and shifts the processing to the S175 when the
startup maintenance condition has not been established. In this
embodiment, the transceiver 41 determines that the startup
maintenance condition has been established, when not receiving the
stop instruction from the MCU 43, and determines that the startup
maintenance condition has not been established to shift the
processing to the S175, when receiving the stop instruction from
the MCU 43.
[0100] In the S175, the transceiver 41 outputs the stop instruction
to the power supply relay 44. Thus, the electric supply to the MCU
43 stops, and the relay device 4 sleeps (that is, performs the
standard sleep).
[0101] [1-3. Processing]
[0102] [1-3-1. The Startup Maintenance Processing by the Terminal
Device]
[0103] The content of the startup maintenance processing executed
by the terminal device 5 will be described below with reference to
the flowchart in FIG. 8. In this embodiment, in the processing
described below, the processing in S200 is executed by the
transceiver 51, and the processing after S210 is executed by the
MCU 53. The terminal device 5 can be configured as appropriate so
that at least part of the processing executed by the MCU 53 is
executed by the hardware.
[0104] In the S200, when the terminal device 5 is in the sleep
state, the transceiver 51 wakes up the terminal device 5 when the
communication frame waking up the self-node is present on the bus
2.
[0105] Like the S100 or the S130 to the S135 illustrated in FIG. 6,
the transceiver 51 determines whether or not the communication
frame waking up the self-node is present on the bus 2. The
communication frame here is any communication frame when the
terminal device 5 performs the standard sleep, and is the NM frame
assigned the startup information designating the self-node when the
terminal device 5 performs the selective sleep. Hereinafter, the NM
frame assigned the startup information designating the self-node is
also referred to as a designation NM frame. In other words, the
startup information designating the self-node is the startup
information designating the startup group including the terminal
device 5. The designation NM frame corresponds to the designation
management frame.
[0106] The terminal device 5 wakes up also when the state where the
network system 1 should be started up (that is, the internal
factor) is detected by the state detection unit 55. In the terminal
device 5, the information representing which of the reception of
the designation NM frame (that is, the external factor) and the
internal factor is the wakeup factor is notified from the power
supply relay 54 to the MCU 53, as described above. Among the wakeup
factors, the factor other than the reception of the designation NM
frame corresponds to the internal factor.
[0107] In the S210, when waking up, the MCU 53 outputs the wakeup
instruction through the signal line 562 to the power supply switch
516 and the state discrimination switch 517. The wakeup instruction
is the instruction that causes the power supply switch 516 to
execute the electric supply to the detection unit 515 and causes
the state discrimination switch 517 to select the detection unit
515 as the transmission source of the startup instruction. Thus,
the MCU 53 operates the transceiver 51 as the PN-compatible
transceiver. That is, the terminal device 5 operates so as to be
compatible with the partial network.
[0108] In the subsequent S220, the MCU 53 determines, on the basis
of the information notified from the power supply relay 54, whether
or not the wakeup factor is the startup factor caused by the
self-node (that is, the internal factor). When determining that the
wakeup factor is the internal factor, the MCU 53 shifts the
processing to the S230. When determining that the wakeup factor is
not the internal factor and is the reception of the designation NM
frame, (that is, the external factor), the MCU 53 shifts the
processing to the S240.
[0109] In the S230, the MCU 53 transmits the NM frame assigned, as
the startup information, the information required for identifying
the startup group to which the terminal device 5 belongs, (that is,
the designation NM frame) to the bus 2, and returns the processing
to the S220. That is, the MCU 53 repeatedly (that is, periodically)
transmits the designation NM frame to the bus 2 while the wakeup
factor is the internal factor. When the wakeup factor is no longer
the internal factor (that is, when the detection of the internal
factor by the state detection unit 55 stops), the MCU 53 stops the
periodical transmission of the designation NM frame to the bus 2,
and shifts the processing to the S240.
[0110] While waking up, the MCU 53 can transmit a typical frame
that is each of various communication frames other than the
designation NM frame, to the buses 2 in order to execute the
function previously assigned to the self-node. The typical frame
can be transmitted while the MCU 53 transmits the designation NM
frame in the S230 (that is, while the terminal device 5 wakes up by
the internal factor). The typical frame can be received and used by
other nodes in the startup group to which the self-node
belongs.
[0111] Hereinafter, the startup group to which the self-node
belongs is also referred to as the same startup group. Also, other
nodes in the startup group to which the self-node belongs are also
referred to as other nodes in the same startup group. That is, the
MCU 53 can receive, from the buses 2, the typical frames
transmitted by other nodes in the same startup group. The MCU 53
may be configured so as not to transmit the typical frame.
[0112] In the S240, the MCU 53 determines whether or not a
non-designation period is operation determination time or more. The
non-designation period is the period during which the NM frame
designating the self-node as a reception target (that is, the
designation NM frame) is absent on the bus 2 (that is, the period
during which the designation NM frame is not received through the
bus 2). The operation determination time is the predetermined time
for detecting that all other nodes in the same startup group have
not started up by the internal factor, and is the time for
determining whether or not the self-node may be caused to
sleep.
[0113] The operation determination time is set to the time longer
than the transmission cycle of the designation NM frame. The
operation determination time can be set to, for example, three
seconds. However, the operation determination time is not limited
to this, and can be arbitrarily set.
[0114] Although not illustrated, by timer processing that is the
processing different from this startup maintenance processing, the
MCU 53 measures, as the non-designation period, the time from the
reception of the designation NM frame to the reception of the next
designation NM frame. In the timer processing, the non-designation
period is reset each time the designation NM frame is received, and
is reset after this startup control processing ends.
[0115] The MCU 53 determines, on the basis of the timer processing,
whether or not the non-designation period is the operation
determination time or more. The MCU 53 returns the processing to
the S220 when the non-designation period is less than the operation
determination time, and shifts the processing to the S250 when the
non-designation period is the operation determination time or
more.
[0116] It is determined as positive in the S240, which means that
all other nodes in the same startup group have not also started up
by the internal factor for the operation determination time or
more, and that like the S250 described later, all other nodes in
the same startup group can also stop the transmission of the
typical frames.
[0117] In the S250, the MCU 53 stops the transmission of all the
communication frames to the buses 2. All the communication frames
are the communication frames other than the designation NM frames
in which the transmission thereof has already been stopped
(hereinafter, the typical frames). When the transmission is
stopped, the communication frames caused by the self-node (that is,
the designation NM frames and the typical frames transmitted by the
internal factor) are not received by all the nodes in the same
startup group.
[0118] Other nodes in the same startup group are configured to
execute the startup maintenance processing like the self-node. The
self-node determines as positive in the S240 to shift to the S250,
which means that other nodes in the same startup group also
performs similar determination at substantially the same timing,
and shift to the S250. That is, other nodes in the same startup
group stop the transmission of the designation NM frames and the
typical frames on the basis of the internal factor of the node at
substantially the same timing.
[0119] Thus, the transmission and reception of the communication
frames between all the nodes in the same startup group stop.
However, the "same timing" here is not limited to the "same timing"
in strict meaning. This is because deviation (that is, an error)
can be caused between the self-node and other nodes in the same
startup group in detecting the timings.
[0120] In the subsequent S260, the MCU 53 is standby for
predetermined spare time. The spare time can be set to, for
example, three seconds. However, the spare time is not limited to
this, and can be arbitrarily set.
[0121] The spare time is the time for inhibiting the influence due
to the caused deviation between the timing at which it is
determined by the self-node that the non-designation period is the
operation determination time or more and the timing at which it is
determined by other nodes in the same startup group that the
non-designation period is the operation determination time or more.
The influence due to the caused deviation means that after it is
determined by the self-node that the non-designation period is the
operation determination time or more, the typical frames from other
nodes in the same startup group are received by the self-node
through the buses 2.
[0122] During the spare time, the terminal device 5 can receive the
typical frames transmitted from other nodes in the same startup
group, but the typical frames received during the spare time may be
used by the terminal device 5, or are not necessarily required to
be used.
[0123] In the subsequent S270, after the non-designation period
continues for the operation determination time, and after further,
the spare time elapses, the MCU 53 measures a transmission path
empty period, and determines whether or not the transmission path
empty period continues for predetermined transition determination
time or more. The transmission path empty period is the period
during which the communication frame is absent on the bus 2, in
other words, the period during which any communication frame is not
transmitted and received on the bus 2 (that is, the period during
which the bus 2 is empty).
[0124] The MCU 53 measures the transmission path empty period by
the processing different from this startup maintenance processing,
for example, by the timer processing by which the measurement time
is reset each time the certain communication frame is received or
at the time of the completion of this startup maintenance
control.
[0125] The transition determination time can be set to, for
example, three seconds. However, the transition determination time
is not limited to this, and can be arbitrarily set. The transition
determination time is the time to monitor the empty state of the
bus 2 in order to decide in which of the standard sleep state and
the selective sleep state the self-node is caused to sleep. The MCU
53 shifts the processing to the S280 when the transmission path
empty period is less than the transition determination time, and
shifts the processing to the S290 when the transmission path empty
period is the transition determination time or more.
[0126] In the S280, the MCU 53 causes the self-node to make a
transition from the wakeup state to the selective sleep state (that
is, causes the self-node to perform the selective sleep).
Specifically, the MCU 53 outputs the first switching instruction to
the power supply switch 516 and the state discrimination switch
517, and outputs the stop instruction to the power supply relay 54.
Thus, the MCU 53 ends this startup control processing.
[0127] Thus, by stopping the electric supply to the MCU 53, the
self-node sleeps. Also, electricity is supplied to the detection
unit 515 by the power supply switch 516, and the detection unit 515
is selected as the transmission source of the startup instruction
by the state discrimination switch 517, so that the transceiver 51
operates as the PN-compatible transceiver. As a result, in
sleeping, the self-node makes a transition to the selective
sleep.
[0128] In the S290, the MCU 53 causes the self-node to make a
transition from the wakeup state to the standard sleep state (that
is, causes the self-node to perform the standard sleep).
Specifically, the MCU 53 outputs the second switching instruction
to the power supply switch 516 and the state discrimination switch
517, and outputs the stop instruction to the power supply relay 54.
Thus, the MCU 53 ends this startup control processing.
[0129] Thus, by stopping the electric supply to the MCU 53, the
self-node sleeps. Also, the electric supply to the detection unit
515 is stopped by the power supply switch 516, and the
transmission/reception circuit 511 is selected as the transmission
source of the startup instruction by the state discrimination
switch 517, so that the transceiver 51 operates as the
PN-incompatible transceiver. As a result, in sleeping, the
self-node makes a transition to the standard sleep.
[0130] [1-3-2. The Monitoring Startup Processing by the Relay
Device]
[0131] The content of the monitoring startup processing executed by
the relay device 4 will be described below with reference to the
flowchart in FIG. 9. In this embodiment, in the processing
described below, the processing in S300 is executed by the
transceiver 41, and the processing after S310 is executed by the
MCU 43. The relay device 4 can be configured as appropriate so that
at least part of the processing executed by the MCU 43 is executed
by the hardware.
[0132] In the S300, when the relay device 4 is in the sleep state,
like the S160 illustrated in FIG. 7, the transceiver 41 determines
whether or not the communication frame waking up the relay device 4
is present on the bus 2. The communication frame here is any
communication frame. When any communication frame is present on the
bus 2, the transceiver 41 wakes up the relay device 4.
[0133] In the S310, after waking up, the MCU 43 continuously
executes the frame relay processing as the processing different
from this monitoring startup processing while waking up.
[0134] In the subsequent S320, the MCU 43 determines whether or not
the period during which any communication frame is not transmitted
and received on the bus 2 (that is, the above-described
transmission path empty period) continues for predetermined
monitoring time or more. The MCU 43 measures the transmission path
empty period by the processing different from this monitoring
startup processing, for example, by the timer processing by which
the measurement time is reset each time the certain communication
frame is received or at the time of the completion of this
monitoring startup processing.
[0135] The monitoring time is the time for determining the timing
at which a particular startup frame is outputted to the bus 2. The
monitoring time is set to the value larger than a preparation time.
The preparation time corresponds to the time obtained by adding the
spare time and the transition determination time described
above.
[0136] The MCU 43 is standby by repeating the same step when the
transmission path empty period is less than the monitoring time,
and shifts the processing to the S330 when the transmission path
empty period is the monitoring time or more.
[0137] In the S330, the MCU 43 transmits the particular startup
frames to all the nodes connected to the buses 2 excluding the
relay device 4. The particular startup frame is a type of the
communication frame, and is the communication frame for waking up
all the nodes connected to the buses 2 excluding the relay device 4
(that is, all the terminal devices 5 connected to the buses 2).
[0138] The particular startup frame may be the communication frame
that has an unused bit of the 8-bit data representing the startup
information and such that 1 is set to the predetermined bit. For
example, in FIG. 3, in the 8-bit data representing the startup
information, the sixth bit counted from the low order may be used
as the bit representing the particular startup frame. Also for the
belonging information stored by each terminal device 5, the same
bit as the bit representing the particular startup frame in the
startup information is assigned as the bit representing the
particular startup frame.
[0139] Thus, both the terminal device 5 performing the standard
sleep and the terminal device 5 performing the selective sleep wake
up by receiving the particular startup frame. The particular
startup frame is not limited to this, and can be configured in
various forms.
[0140] The terminal device 5 that has woken up by the particular
startup frame, after having woken up by the particular startup
frame, makes a transition to the standard sleep when detecting that
the non-designation period continues for the operation
determination time or more and that the transmission path empty
period continues for the preparation time or more. In other words,
when after the transmission of the particular startup frame, the
transmission path empty period successively continues for the
operation determination time or more and the preparation time or
more, all the terminal devices 5 make a transition to the standard
sleep.
[0141] In the S340, the MCU 43 is standby for predetermined
re-startup time. In this embodiment, the re-startup time is set to
the value larger than the time obtained by adding the operation
determination time and the preparation time described above. The
re-startup time may be 0.
[0142] In the S350, the MCU 43 outputs the stop instruction to the
power supply relay 44. Thus, the electric supply to the MCU 43
stops, and the relay device 4 sleeps. The transceiver 41 included
in the relay device 4 is the PN-incompatible transceiver, so that
in sleeping, the relay device 4 performs the standard sleep. That
is, the relay device 4 performs the standard sleep, so that all the
nodes of the network system 1 perform the standard sleep.
[0143] [1-4. Operation]
[0144] [1-4-1. The Operation of the Terminal Device]
[0145] The operation of the terminal device 5 (that is, the
self-node) will be described with reference to FIG. 10. In FIG. 10,
the operation determination time is represented as TA, the spare
time is represented as TB, the transition determination time is
represented as TC, and the preparation time is represented as TD.
FIG. 10 illustrates the state where a designation NM frame 501 is
transmitted and received on the bus 2 at time t1, the operation
determination time TA or more elapses, and successively, the
designation NM frame is not transmitted and received on the bus 2.
The time at which the operation determination time TA elapses from
the time t1 at which the designation NM frame 501 is transmitted
and received on the bus 2 is time t2. The time at which the spare
time TB elapses from the time t2 is time t3. The time at which the
transition determination time TC elapses from the time t3 is time
t4.
[0146] The designation NM frames and the typical frames that are
illustrated are the communication frames to be received by the
nodes in the same startup group. The transmission source may be the
self-node, or may be other nodes in the same startup group.
[0147] Only the typical frames can be transmitted and received on
the bus 2 from the time t1 at which the self-node detects the
designation NM frame most recently, to the time t2 at which the
period during which the reception of the designation NM frame is
not detected (that is, the non-designation period) continues for
the operation determination time TA.
[0148] At the time t2, the self-node stops the transmission of all
the communication frames. At substantially the same timing as the
time t2, the transmission of all the communication frames is
similarly stopped in other nodes in the same startup group. With
allowance, the self-node determines in which of the states the
self-node is caused to sleep, according to the state of the bus 2
after the time t3 that is the time at which the spare time TB
elapses from the time t2.
[0149] The period to monitor the empty state of the bus 2 is from
the time t3 to the time t4 at which the transition determination
time TC elapses, in order to determine in which of the states the
self-node is caused to sleep. Here, when the bus 2 is not in the
empty state from the time 13 to the time t4 at which the transition
determination time TC elapses, the self-node makes a transition to
the selective sleep after the time t4. The bus 2 is not in the
empty state, which means that any communication frame is
transmitted and received on the bus 2. On the other hand, when the
bus 2 is in the empty state during this time, the self-node makes a
transition to the standard sleep after the time t4.
[0150] [1-4-2. The Operation of the Network System]
[0151] The operation of the network system 1 will be described with
reference to FIG. 11. Like FIG. 10, FIG. 11 illustrates the
operation of the terminal devices 5. However, FIG. 11 illustrates
the operation of each of the terminal devices 5 belonging to the
startup groups GrA, GrB, and GrC. The NM frame including the
startup information designating the startup group a is represented
as "NM PNC_.alpha.=1", and the NM frame not including the startup
information designating the startup group a is represented as "NM
PNC_.alpha.=0". However, .alpha.=A, B, C, . . . .
[0152] For example, NM PNC_A=1 is the NM frame including the
startup information designating the startup group GrA, and in other
words, is the designation NM frame with respect to the terminal
device 5 belonging to the startup group GrA.
[0153] The terminal device 5 belonging to the startup group GrA
operates like FIG. 10. Here, t11, t12, t13, and t14 correspond to
the t1, t2, t3, and t4 in FIG. 10, respectively. In FIG. 11, the
communication frame is transmitted and received on the bus 2
between the time t13 and the time t14, so that the terminal device
5 belonging to the startup group GrA makes a transition to the
selective sleep after the time 114. The communication frames
transmitted and received on the bus 2 here are, for example, "NM
PNC B=1" and "NM PNC_C=1" in FIG. 11.
[0154] The terminal device 5 belonging to the startup group GrB
also operates like FIG. 10. Here, t21, t22, t23, and t24 correspond
to the t1, t2, t3, and t4 in FIG. 10, respectively. In FIG. 11, the
communication frame is transmitted and received on the bus 2
between the time t23 and the time t24, so that the terminal device
5 belonging to the startup group GrB makes a transition to the
selective sleep after the time t24. The communication frames
transmitted and received on the bus 2 here are, for example, the
typical frame and "NM PNC_C=0" in FIG. 11.
[0155] The terminal device 5 belonging to the startup group GrC
also operates almost similarly to FIG. 10. Here, t31, t32, t33, and
t34 correspond to the t1, t2, t3, and t4 in FIG. 10, respectively.
However, in FIG. 11, the bus 2 is in the empty state between the
time t33 and the time t34, so that the terminal device 5 belonging
to the startup group GrC makes a transition to the standard sleep
after the time t34.
[0156] In other words, in the network system 1, among the plurality
of terminal devices 5 connected to the buses 2, the terminal device
5 sleeping last performs the standard sleep. Thus, in the network
system 1, at least the terminal device 5 sleeping last performs the
standard sleep, so that power consumption in the sleep state is
reduced. That is, in the network system 1, power consumption is
reduced corresponding to at least the terminal device 5 sleeping
last.
[0157] In the network system 1 of this embodiment, the relay device
4 measures the transmission path empty period like the terminal
device 5, and outputs the particular startup frame when the
transmission path empty period continues for the monitoring time or
more. For example, the bus 2 is in the empty state after the time
134 in FIG. 11, so that the relay device 4 outputs the particular
startup frame at the time t41 at which the monitoring time elapses
from the time t34. Thus, in the network system 1, all the terminal
devices 5 that are all the nodes wake up.
[0158] At the time t41, each of all the terminal devices 5 that
have woken up by the particular startup frame executes the
above-described startup maintenance processing, and makes a
transition to the standard sleep since the bus 2 is in the empty
state. In FIG. 11, all the terminal devices 5 in the startup groups
GrA to GrC make a transition to the standard sleep after the time
t42. However, deviation can be caused between the timings at which
the respective terminal devices 5 make a transition to the standard
sleep. Further, after the time t41 at which the particular startup
frame is transmitted, the relay device 4 sleeps after being standby
for the re-startup time.
[0159] In this way, in the network system 1, when the empty state
of the buses 2 continues, all the terminal devices 5 that are all
the nodes connected to the buses 2 make a transition to the
standard sleep. Thus, in the network system 1 that is the partial
network, power consumption when the terminal devices 5 are in the
sleep state is reduced.
[0160] Further, in the network system 1, after all the terminal
devices 5 make a transition to the standard sleep by the reception
of the particular startup frame, the relay device 4 also makes a
transition to the standard sleep. Thus, all the nodes and the relay
device 4 of the network system 1 perform the standard sleep, and
power consumption when the terminal devices 5 are in the sleep
state is further reduced in the network system 1.
[0161] [1-5. Effects]
[0162] According to the first embodiment described above in detail,
the following effects are exerted.
[0163] (1a) In the terminal device 5 included in the network system
1, the transceiver 51 has the first standby unit and the second
standby unit. The first standby unit receives the designation NM
frame, and then causes the terminal device 5 to make a transition
from the sleep state to the wakeup state. The second standby unit
receives any communication frame, and then causes the terminal
device 5 to make a transition from the sleep state to the wakeup
state.
[0164] The transceiver 51 operates one of the first standby unit
and the second standby unit according to the switching instruction.
The transceiver 51 operates as the PN-compatible transceiver
causing the terminal device 5 to make a transition to the selective
sleep at the time of the operation of the first standby unit, and
operates the terminal device 5 as the PN-incompatible transceiver
causing the terminal device 5 to make a transition to the standard
sleep at the time of the operation of the second standby unit.
[0165] Since the second standby unit includes some configurations
included in the first standby unit, power consumption is lower in
the case of using the transceiver 51 as the PN-incompatible
transceiver by operating the second standby unit than in the case
of using the transceiver 51 as the PN-compatible transceiver by
operating the first standby unit.
[0166] In the MCU 53 of the terminal device 5, when the terminal
device 5 wakes up by the internal factor, a startup processing unit
periodically transmits the designation NM frame to the bus while
the internal factor continues, and does not transmit the
designation NM frame to the bus 2 when the internal factor is not
caused. The S220 to the S230 correspond to the processing as the
startup processing unit. That is, the terminal device 5 starting up
by the internal factor can wake up the terminal devices 5 included
in the same startup group while the designation NM frame is
transmitted.
[0167] In other words, when the terminal device 5 starting up by
the internal factor stops the transmission of the designation NM
frame, the continuous wake-up of the terminal devices 5 included in
the same startup group are also stopped by the reception of the
designation NM frame.
[0168] In the MCU 53, after the non-designation period during which
the designation NM frame is not received through the bus 2 becomes
the operation determination time or more, a switching unit
determines whether or not the transmission path empty period
continues for the preparation time or more. The MCU 53 outputs, to
the transceiver 51, the second switching instruction that is the
switching instruction operating the second standby unit when the
transmission path empty period continues for the preparation time
or more. In this embodiment, the time obtained by adding the spare
time and the transition determination time corresponds to the
preparation time. The S240 to the S290 correspond to the processing
as the switching unit.
[0169] According to such a configuration, the terminal device 5 is
configured so as to be able to switch the first standby unit and
the second standby unit. Thus, power consumption can be reduced,
for example, in sleeping, by operating the second standby unit
rather than by operating the first standby unit.
[0170] Further, when the non-designation period becomes the
operation determination time or more, and the transmission path
empty period continues for the preparation time or more, the
terminal device 5 operates the second standby unit in sleeping. In
other words, the terminal device 5 makes a transition to the
standard sleep when other terminal devices 5 in the same startup
group do not wake up by the internal factor, the terminal device 5
is brought into the state where the terminal device 5 may cause to
sleep, and the state where the bus 2 is empty then continues. As a
result, in the network system 1, power consumption can be reduced
corresponding to the standard sleep performed by the terminal
device 5.
[0171] For example, when electricity is not supplied for a long
period to the vehicle equipped with the network system 1 (that is,
more specifically, the terminal device 5), the effect of reducing
power consumption is further exerted. The long period here can
include various periods, such as, for example, the period during
which the vehicle is parked, and the period during which the
vehicle is transported.
[0172] (1b) The MCU 53 measures the non-designation period. In the
MCU 53, an empty period determination unit, after the
non-designation period becomes the operation determination time or
more, determines whether or not the transmission path empty period
is the preparation time or more. The S240 corresponds to the
processing as an empty period determination unit. In the MCU 53, a
first switching execution unit outputs the first switching
instruction to the transceiver 51 when after the non-designation
period continues for the operation determination time or more, it
is determined that the transmission path empty period is less than
the preparation time. The S280 corresponds to the processing as the
first switching execution unit. The first switching instruction is
the switching instruction for operating the first standby unit.
[0173] In the S290, the MCU 53 outputs the second switching
instruction to the transceiver 51 when after the non-designation
period continues for the operation determination time or more, it
is determined that the transmission path empty period is the
preparation time or more. The S290 corresponds to the processing as
a second switching execution unit.
[0174] According to such a configuration, the terminal device 5
makes a transition to the selective sleep. Thus, the network system
1 can be successively operated as the partial network system by
using the terminal device 5.
[0175] (1c) The network system 1 includes the relay device 4. The
MCU 43 of the relay device 4 includes a monitoring startup unit.
The monitoring startup unit measures the transmission path empty
period. The monitoring startup unit transmits the particular
startup frame when the predetermined condition in which the
transmission path empty period continues for the monitoring time or
more longer than the above-described preparation time is satisfied.
S440 corresponds to the processing as the monitoring startup unit.
The particular startup frame is a type of the communication frame,
and is the communication frame for waking up all the nodes. In this
embodiment, the relay device 4 is not included in each of all the
nodes here.
[0176] According to such a configuration, even if the terminal
device 5 performing the selective sleep and the terminal device 5
performing the standard sleep are mixed in the network system 1,
all the terminal devices 5 can be woken up by the particular
startup frame.
[0177] (1d) The first standby unit and the second standby unit of
the terminal device 5 causes the terminal device 5 to make a
transition from the sleep state to the wakeup state by the
reception of the particular startup frame. When making a transition
to the wakeup state by the reception of the particular startup
frame, the terminal device 5 outputs the second switching
instruction to the transceiver 51 when the non-designation period
becomes the operation determination time or more, and it is
determined that the transmission path empty period is the
preparation time or more.
[0178] According to such a configuration, each of all the terminal
devices 5 that have received the particular startup frame and made
a transition to the wakeup state makes a transition to the standard
sleep when the transmission path is continuously empty after the
reception of the particular startup frame. That is, all the
terminal devices 5 of the network system 1 perform the standard
sleep, so that in the network system 1, power consumption when the
terminal devices 5 are in the sleep state can be further
reduced.
[0179] (1e) The relay device 4 determines whether or not, after the
transmission of the particular startup frame, the transmission path
empty period successively continues for the re-startup time or more
larger than the value obtained by adding the operation
determination time and the preparation time, and when the
transmission path empty period successively continues for the
re-startup time or more, makes a transition to the standard sleep.
Since the re-startup time is larger than the value obtained by
adding the operation determination time and the preparation time,
the relay device 4 can perform the standard sleep after all the
terminal devices 5 that have woken up by the reception of the
particular startup frame perform the standard sleep.
[0180] According to such a configuration, the relay device 4 and
all the nodes perform the standard sleep in the network system 1.
Thus, power consumption when the terminal devices 5 are in the
sleep state can be further reduced in the network system 1.
2. Second Embodiment
[0181] [2-1. The Point Different from the First Embodiment]
[0182] The second embodiment has the same basic configuration as
the first embodiment, and thus, the different point will be
described below. The same reference numerals as the first
embodiment denote the same configurations, and the previous
description is referred. This is ditto for a third embodiment or
later.
[0183] In the above-described first embodiment, the relay device 4
has the monitoring function and the all wakeup function. On the
other hand, the second embodiment is different from the first
embodiment in that in place of the relay device 4, the terminal
device 5 includes the monitoring function and the all wakeup
function.
[0184] For example, as illustrated in FIG. 12, a network system 1a
of the second embodiment includes the plurality of buses 2 and the
plurality of terminal devices 5 like the first embodiment, but does
not include the relay device 4. The bus 21 to the bus 2_3 are
connected to be able to communicate with each other. Although the
plurality of buses 2 are illustrated in FIG. 12, the number of
buses 2 may be one in the network system 1a of the second
embodiment.
[0185] In the network system 1a of the second embodiment, the
terminal device 5 has the monitoring function and the all wakeup
function, and the terminal device 5 that has made a transition to
the sleep state last executes the monitoring function and the all
wakeup function.
[0186] [2-2. The Startup Maintenance Processing by the Terminal
Device]
[0187] The content of the startup maintenance processing executed
by the terminal device 5 of the second embodiment will be described
with reference to the flowchart in FIG. 13. The startup maintenance
processing of the second embodiment illustrated in FIG. 13 is
different from the startup maintenance processing of the first
embodiment illustrated in FIG. 8 in that the S210 is replaced with
S215 and S272 to S276 are added.
[0188] In the S200, the transceiver 51 determines whether or not
the communication frame waking up the self-node is present on the
bus 2. Similar to the first embodiment, the transceiver 51 wakes up
also by the reception of the particular startup frame also when the
transceiver 51 performs the selective sleep or the standard
sleep.
[0189] In the S215, when waking up, the MCU 53 executes the same
processing as the S210 illustrated in FIG. 8, and stores, in the
memory 532, whether or not the wakeup in this step is the wakeup by
the particular startup frame. For example, similar to the first
embodiment, when the information representing whether or not the
communication frame is the particular startup frame is included in
the startup information, the MCU 53 may store the startup
information of the received designation NM frame in the memory 532
in this step.
[0190] In the subsequent S220 to S260, the MCU 53 operates as with
the S220 to the S260 of the first embodiment. That is, the MCU 53
detects that after the stop of the transmission of the designation
NM frame, the non-designation period continues for the operation
determination time or more, stops the transmission of the
communication frames, and thereafter, is standby for the spare
time, thereby shifting the processing to the S270.
[0191] Here, in the S270, when the transmission path empty period
is less than the transition determination time, the MCU 53 shifts
the processing to the S280, and causes the terminal device 5 to
perform the selective sleep. On the other hand, in the S270, when
it is determined that the transmission path empty period is the
transition determination time or more, the MCU 53 shifts the
processing to the S272.
[0192] In the S272, the MCU 53 determines whether or not the wakeup
in the S215 is caused by the particular startup frame.
[0193] Here, the MCU 53 shifts the processing to the S276 when the
wakeup in the S215 is caused by the particular startup frame. The
MCU 53 is standby while the transmission path empty period
continues for the transition determination time in the S276, and
shifts the processing to the S290. In the S290, the MCU 53 performs
the standard sleep. Thus, the MCU 53 ends the startup maintenance
processing.
[0194] On the other hand, when the wakeup in the S215 is not caused
by the particular startup frame, the MCU 53 shifts the processing
to the S274, transmits the particular startup frame to the bus 2 in
the S274, and shifts the processing to the S276. After the S276,
the MCU 53 is standby while the transmission path empty period
continues for the transition determination time, as described
above, and performs the standard sleep. Thus, the MCU 53 ends the
startup maintenance processing.
[0195] [2-3. Operation]
[0196] The operation of the network system 1a will be described
below. Here, in the network system 1a, in the terminal devices 5
other than the terminal device 5 attempting to make a transition to
the sleep last, similar to the first embodiment, the MCUs 53
execute the processing in the S270 to the S280, and cause the
terminal devices 5 to perform the selective sleep once.
[0197] On the other hand, since other terminal devices 5 perform
the selective sleep, the MCU 53 of the terminal device 5 attempting
to sleep last in the network system 1a shifts the processing to the
S272.
[0198] In the S272, the MCU 53 of the above-described terminal
device 5 attempting to sleep last determines whether or not the
wakeup in the S215 is caused by the particular startup frame. The
MCU 53 determines that the wakeup is not caused by the particular
startup frame, shifts the processing to the S274, and transmits the
particular startup frame to the bus 2. The particular startup frame
is the communication frame for waking up all the terminal devices
5, but even if the particular startup frame is received by the
terminal device 5 that has already woken up, such the reception of
the particular startup frame does not affect the processing in the
subsequent terminal device 5 at all.
[0199] The MCU 53 of the above-described terminal device 5
attempting to sleep last shifts the processing to the S276 after
the transmission of the particular startup frame to the bus 2, is
standby in the S276 while the transmission path empty time
continues for the transition determination time, and shifts the
processing to the S290 to perform the standard sleep.
[0200] When the particular startup frame is transmitted, the
terminal devices 5 other than the above-described terminal device 5
attempting to make a transition to the sleep last, which have
already performed the selective sleep wake up once. The MCU 53 of
each of these terminal devices 5 that have woken up by the
particular startup frame executes the startup maintenance
processing.
[0201] That is, the MCU 53 of each of the terminal devices 5 that
have woken up by the particular startup frame determines that the
non-designation period continues for the operation determination
time or more and that the transmission path empty period continues
for the preparation time or more, and in the S272, determines that
the startup factor of the terminal device is the particular startup
frame. The MCU 53 shifts the processing to the S276, is standby in
the S276 while the transmission path empty time continues for the
transition determination time, and shifts the processing to the
S290 to perform the standard sleep.
[0202] Thus, since in the network system 1a, all the terminal
devices 5 perform the standard sleep, power consumption when the
terminal devices 5 are in the sleep state is reduced in the network
system 1.
[0203] [2-4. Effect]
[0204] According to the second embodiment described above in
detail, the effect (1a) of the above-described first embodiment is
exerted, and further, the following effect is exerted.
[0205] (2a) The network system 1a includes the plurality of buses 2
and the plurality of terminal devices 5. The MCU 53 of each of the
terminal devices 5 measures the non-designation period. In the MCU
53, a startup storage unit stores whether or not the terminal
device 5 has woken up by the particular startup frame. The S215
corresponds to the processing as the startup storage unit. In the
MCU 53, a startup determination unit determines whether or not the
terminal device 5 has woken up by the particular startup frame. The
S272 corresponds to the processing as the startup determination
unit.
[0206] In the MCU 53, the switching unit transmits the particular
startup frame when the non-designation period becomes the operation
determination time or more, the transmission path empty period is
the preparation time or more, and it is determined that the
terminal device has not woken up by the particular startup frame.
Also, when the terminal device 5 makes a transition to the wakeup
state by the reception of the particular startup frame, the
non-designation period continues for the operation determination
time or more, and the transmission path empty period continues for
the preparation time or more, it is determined that the terminal
device 5 has woken up by the particular startup frame, so that the
MCU 53 outputs the second switching instruction to the transceiver
51.
[0207] According to such a configuration, all the terminal devices
5 of the network system 1a can be caused to perform the standard
sleep without including the relay device. That is, the system
configuration can be simplified, and further, power consumption can
be reduced.
[0208] In this embodiment, when the non-designation period becomes
the operation determination time or more, and the transmission path
empty period is the preparation time or more, it is determined that
the terminal device has not woken up by the reception of the
particular startup frame, which corresponds to the predetermined
condition.
3. Third Embodiment
[0209] [3-1. The Point Different from the First Embodiment]
[0210] In the above-described first embodiment, when not receiving
the designation NM frame for the predetermined time (that is, the
operation determination time) or more, the terminal device 5 makes
a transition to one of the selective sleep and the standard sleep
according to the empty state of the bus 2. On the other hand, the
third embodiment is different from the first embodiment in that
when not receiving the designation NM frame for the predetermined
time or more, the terminal device 5 makes a transition to the
selective sleep irrespective of the empty state of the bus 2. The
relay device 4 of the third embodiment is configured like the first
embodiment in that the relay device 4 monitors the empty state of
the bus 2, and transmits the particular startup frame to the bus 2
when the empty state of the bus 2 continues for the predetermined
monitoring time or more. For example, the preparation time
corresponds to the monitoring time.
[0211] For example, although not illustrated, a network system 1b
of the third embodiment includes the plurality of buses 2, the
plurality of terminal devices 5, and the relay device 4 like the
network system 1 of the first embodiment illustrated in FIG. 1.
[0212] [3-2. The Startup Maintenance Processing by the Terminal
Device]
[0213] The content of the startup maintenance processing executed
by the terminal device 5 of the third embodiment will be described
with reference to the flowchart in FIG. 14. In the startup
maintenance processing illustrated in FIG. 14, the S210 in the
startup maintenance processing of the first embodiment illustrated
in FIG. 8 is replaced with the S215, and the S270 is replaced with
the S272. Since the S200 to the S260 are the same as the S200 to
the S260 of the second embodiment illustrated in FIG. 13, the
description is simplified here.
[0214] In the S215 to the S260, when the non-designation period
continues for the operation determination time or more, the MCU 53
of the terminal device 5 stops the transmission of the
communication frame, and thereafter, is standby for the spare time,
thereby shifting the processing to the S272.
[0215] In the S272, the MCU 53 determines whether or not the wakeup
in the S215 is caused by the particular startup frame.
[0216] Here, when the wakeup in the S215 is not caused by the
particular startup frame, the MCU 53 shifts the processing to the
S280, and causes the terminal device 5 to perform the selective
sleep in the S280. Thus, the MCU 53 ends the startup maintenance
processing.
[0217] On the other hand, when the wakeup in the S215 is caused by
the particular startup frame, the MCU 53 shifts the processing to
the S290, and causes the terminal device 5 to perform the standard
sleep in the S290. Thus, the MCU 53 ends the startup maintenance
processing.
[0218] The relay device 4 executes the monitoring startup
processing illustrated in FIG. 9 like the relay device 4 of the
first embodiment.
[0219] [3-3. Operation]
[0220] The operation of the network system 1b will be described
below. Unlike the first embodiment and the second embodiment, in
the network system 1b, all the terminal devices 5 perform the
selective sleep once. That is, both the terminal device 5
attempting to sleep last and the terminal devices 5 other than the
terminal device 5 attempting to make a transition to the sleep last
perform the selective sleep once. When receiving the particular
startup frame from the relay device 4 monitoring the empty state of
the bus 2, each of all these terminal devices 5 that have performed
the selective sleep wakes up, and performs the standard sleep when
thereafter, the state where the bus 2 is empty continues.
[0221] [3-4. Effect]
[0222] According to the third embodiment described above in detail,
the effect (1a) of the above-described first embodiment is exerted,
and further, the following effect is exerted.
[0223] (3a) The network system 1b includes the plurality of buses
2, the plurality of terminal devices 5, and the relay device 4. The
network system 1b includes at least one monitoring startup unit.
The monitoring startup unit measures the transmission path empty
period, and transmits the particular startup frame when the
transmission path empty period is at least the monitoring time or
more longer than the preparation time. In this embodiment, the
relay device 4 includes the monitoring startup unit. The S330
executed by the MCU 43 corresponds to the monitoring startup
unit.
[0224] In the MCU 53 of the terminal device 5, the startup storage
unit stores whether or not the terminal device 5 has woken up by
the particular startup frame. In the MCU 53, the startup
determination unit determines whether or not the terminal device 5
has woken up by the particular startup frame.
[0225] Here, in the MCU 53, the switching unit transmits the first
switching instruction when after the terminal device makes a
transition to the wakeup state, at least the non-designation period
becomes the operation determination time or more, and it is then
determined that the terminal device 5 has woken up by the
communication frame other than the particular startup frame. On the
other hand, when it is determined that the terminal device 5 has
woken up by the particular startup frame, the second switching
instruction is outputted to the transceiver 51.
[0226] According to the network system 1b configured in this way,
the processing of the terminal device 5 can be simplified.
4. Fourth Embodiment
[0227] In the above-described first embodiment, the second
switching instruction is the switching instruction for supplying
electricity to the second standby unit. On the other hand, the
fourth embodiment is different from the first embodiment in that
the terminal device 5 outputs, as the second switching instruction,
the switching instruction for supplying, to the second standby
unit, a clock signal for driving the second standby unit.
[0228] For example, as illustrated in FIG. 15, in a transceiver 51a
included in a terminal device 5a of the fourth embodiment, the
power supply switch 516 of the transceiver 51 illustrated in FIG. 5
is replaced with a clock switch 516a, and a clock generation
circuit 518 is added.
[0229] The clock generation circuit 518 generates the clock signal
for operating the transmission/reception circuit 511 and the
detection unit 515. Like the execution and stop of the electric
supply to the detection unit 515 by the power supply switch 516
according to the switching instruction, the clock switch 516a
executes and stops the supply of the clock signal to the detection
unit 515 according to the switching instruction.
[0230] The detection unit 515 of the transceiver 51a stops the
operation when the supply of the clock signal is stopped. That is,
in the transceiver 51a, the supply of the clock signal is stopped,
so that power consumption is reduced when the transceiver 51a
operates as the PN-compatible transceiver, in other words, when the
terminal device 5a performs the selective sleep.
[0231] When the terminal device 5 is configured in this way, the
power consumption of the terminal device 5 at the time of
performing the selective sleep can be reduced without stopping the
electric supply to the detection unit 515.
5. Other Embodiments
[0232] The embodiments of this disclosure have been described
above, but this disclosure is not limited to the above-described
embodiments, and can be variously modified and embodied.
[0233] (5a) In the above-described embodiments, the example in
which the terminal device 5 is the ECU has been described, but this
disclosure is not limited to this. At least one of the terminal
devices 5 may be the GW that communicatably connects the plurality
of buses 2 to which the terminal devices 5 are connected.
[0234] (5b) In the above-described first embodiment, the network
system 1 includes one relay device 4 executing the monitoring
control processing, but may include a plurality of relay devices 4
executing the same monitoring control processing as the relay
device 4. In the above-described embodiments, the transceiver 41
included in the relay device 4 is the PN-incompatible transceiver,
but the transceiver 41 may be the PN-compatible transceiver.
[0235] In addition, in the above-described third embodiment, in the
network system 1b, at least one predetermined terminal device 5 of
the plurality of terminal devices 5 may be further configured to
execute the same monitoring startup processing as the relay device
4 of the third embodiment in place of the startup maintenance
processing. The transceiver included in the terminal device 5 may
be configured as the same PN-incompatible transceiver as the
transceiver 41. Alternatively, in the network system 1b, in place
of the relay device 4, at least one predetermined terminal device 5
of the plurality of terminal devices 5 may be configured to execute
the same monitoring startup processing as the relay device 4 of the
third embodiment in place of the startup maintenance processing. In
this case, the relay device 4 is not necessarily required to
execute the monitoring startup processing. The network system 1b
may include the relay device 4, or is not necessarily required to
include the relay device 4.
[0236] (5c) In the above-described embodiments, the transceiver 51
of the terminal device 5 performing the standard sleep wakes up by
the reception of any communication frame, and after waking up,
operates as the PN-compatible transceiver by the wakeup instruction
from the MCU 53. However, this disclosure is not limited to this.
For example, the transceiver 51 performing the standard sleep may
wake up by the reception of any communication frame, operate as the
PN-incompatible transceiver as-is, and receive the same instruction
as the wakeup instruction from the MCU 53 at any timing to be
replaced with the PN-compatible transceiver.
[0237] (5d) The MCU 43, the MCU 53, and the technique thereof
described in this disclosure may be achieved by a dedicated
computer provided by configuring a processor and a memory
programmed to execute one or a plurality of functions embodied by a
computer program. Alternatively, the MCU 43, the MCU 53, and the
technique thereof described in this disclosure may be achieved by a
dedicated computer provided by configuring a processor by one or
more exclusive hardware logic circuits. Alternatively, the MCU 43,
the MCU 53, and the technique thereof described in this disclosure
may be achieved by one or more dedicated computers configured of
the combination of a processor and a memory programmed to execute
one or a plurality of functions and a processor configured of one
or more hardware logic circuits. In addition, a computer program
may be stored, as an instruction executed by a computer, in a
computer-readable non-transitory tangible storage medium. The
technique for achieving the function of each portion included in
the MCU 43 and the MCU 53 is not necessarily required to include
software, and all the functions thereof may be achieved by using
one or a plurality of hardware.
[0238] (5e) A plurality of functions that one component in the
above-described embodiments has may be achieved by a plurality of
components, or one function that one component has may be achieved
by a plurality of components. Also, a plurality of functions that a
plurality of components have may be achieved by one component, or
one function achieved by a plurality of components may be achieved
by one component. Also, part of the configuration of each of the
above-described embodiments may be omitted. Also, at least part of
the configuration of each of the above-described embodiments may be
added to or replaced with the configurations of other embodiments
described above.
[0239] (5f) In addition to each of the above-described network
systems, this disclosure can also be achieved in various forms,
such as the terminal device and the relay device configuring the
network system, the program for functioning the computer as the
terminal device and the relay device, the non-transitory tangible
storage medium, such as the semiconductor memory recording this
program, and the startup control method.
* * * * *